The present invention relates to a device for receiving data and in particular to an opto-electric device which analyzes a random spectral content of a light band. The received spectrum of radiant energy is manipulated (demultiplexed) to determine its individual spectral components. The spectral components are focused onto a multiplicity of individual opto-electric conversion devices which subsequently contain the electric data which emulates from the optic spectrum.
Many applications require the transmission of data between remote points. The most common methods of transmitting data are electrical conductors and by means of modulated radio frequency signals. Both of these methods of transmitting data are subject to electro-magnetic noise, radiation, lightning and other induced electrical effects. To overcome these problems, there has occurred substantial development of optical transmission media, such optical methods typically incorporating modulated laser beams and optic fibers.
It is further common to multiplex signals transmitted by means of a single transmitting medium. Typically, such multiplexing is accomplished utilizing well known sampling techniques wherein a multiplicity of signals are imposed on a single carrier and subsequently separated and demodulated at an intelligence receiving device. This type of signal multiplexing requires the use of sophisticated electronic equipment at both the transmitting and receiving stations. Noise and other interference problems may be aggravated in a multiplexed data transmission line.
When the data being transmitted is in the form of binary coded signals, serial multiplexing of the signals reduces the speed at which information can be transmitted from one point to another. Parallel transmission of binary signals can reduce this time factor but requires an attendant increase in the number of conductors or other data transmission media.
Lastly, there are many applications of electronic devices in which data is sensed at a remote point and in a very hostile environment. For example, a gas turbine engine utilizing an electronic engine control requires the sensing of various turbine parameters such as temperature, mass air flow, speed and the like and the transmission of the sensed data to a remotely located electronic engine control. The sensors must be located on or adjacent to the gas turbine. The sensors and associated data transmitting devices must be capable of reliable operation in the hostile temperature while being subjected to, vibration and pressure environment of the engine. EMI, EMP and other induced electrical noise can seriously degrade system performance.
There therefore exists a need to provide a device that is capable of receiving large quantities of data from one point to another at high speed and with minimum susceptibility to environmental effects. It is further desirable that this mechanism be of small size, highly resistant to hostile environments, and capable of manufacture at reasonable cost.
Broadly, the present invention is an optical spectrum data demodulation device which receives a source of light with random spectral components having a the predetermined spectral band width; means for dispersing the beam as a function of the wave length to generate a light spectrum; detector means for sensing any portion or portions of a continuous spectrum; and a processing means for generating digital data from the optical spectra. The beam of radiant energy comprising individually modulated spectral elements is transmitted via a fiber optic conductor.
It is therefore an object of the invention to provide an improved data receiving device.
It is a further object of this invention to provide a data receiving device with a multi-mode fiber medium for receiving modulated signals.
Another object of the invention is to provide such a device which utilizes a geodesic lens to collimate an input light beam and prevent the dispersion of the multi-mode input signal.
Still another object of the invention is to provide a device which utilizes a grating member formed vertically in a plane perpendicular to a horizontal plane of an guide where the grating disperses a collimated beam from an input source into continuous spectrum.
Yet another object of the invention is to use a curved reflector to focus each individual color from the spectrum uniformly to a unique point on a detector array.